Portable chemical toilet tank



FIG. 1 is a plan view of a portable chemical toilet tank showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a left end elevational view thereof;

FIG. 5 is a right end elevational view thereof; and

FIG. 6 is a rear elevational view thereof. 

The ornamental design for a portable chemical toilet tank, substantially as shown. 